Improving Out-of-Hospital Cardiac Arrest Survival Rates—Optimization Given Constraints

Abstract

Each year, there are nearly 400 000 out-of-hospital cardiac arrest (OHCA) events in the US. 1 The national survival to discharge rate was less than 10% in 2020, 2 and survival varies considerably between communities. 3 Survival rates from OHCA in the US are low since less than 40% receive bystander cardiopulmonary resuscitation (CPR) and much fewer receive use of an automated external defibrillator (AED) in the field before arrival by emergency medical services (EMS). EMS response times vary enormously based on geographic location, and often by the time of EMS arrival, the patient with OHCA has experienced overwhelming ischemic injury and no longer can be resuscitated. The availability of AEDs is a special challenge: availability is limited near the 70% of OHCAs that happen in private residences, many public locations do not have AEDs, even if there is an AED nearby a bystander may not be aware, and many bystanders do not feel confident in using an AED in emergency situations.For years, resuscitation science experts have posited that if we could increase bystander CPR rates and use of AEDs by first responders in the field, OHCA survival rates could be significantly improved. The experience in countries such as Sweden, in which bystander CPR rates are over 50% and survival to discharge rates are over 20%, supports this assertion. 4 The study by Berglund et al 5 takes this logic a step forward in creatively leveraging a mobile telephone app that geolocates AEDs in Sweden using a national AED registry and linking these data with nearly 44 000 citizens trained in bystander CPR in 2 Swedish cities connected through a smartphone system (Heartrunner). This infrastructure served as the platform for a randomized clinical trial in which, in addition to dispatching EMS when notified of an OHCA, emergency dispatchers randomly provided volunteer responders with either alerts asking them to run to the OHCA to provide CPR (control group) or instructed 4 of the 5 closest identified trained bystanders to go get the nearest AED (route illustrated via geolocation software) with the closest individual instructed to go immediately to the OHCA to provide CPR (intervention group). While well designed and using motivated responders, the top-line result is that this increased AED application by the volunteers from only 9.5% to 13.2% (P = .08) before EMS arrival. Only 3.7% of those in the intervention group and 3.9% in the control group received defibrillation before arrival of EMS (P = .99). The proportion of patients who received bystander CPR was 69% in the intervention group and 71% in the control group (P = .42). When volunteer responders arrived first on the scene, the odds ratio for attachment of an AED was 5.2 (95% CI, 3.1-8.8) and for cardiac arrest: nationwide observational study.

Chronic Neuroinflammation and Cognitive Decline in Patients with Cardiac Disease: Evidence, Relevance, and Therapeutic Implications

“…After cardiac arrest, the initial survival of patients is limited by brain death and severe neurological damage, either mandatorily (in the case of brain death) or potentially (in the case of severe damage and corresponding presumed patient wish) [ 50 ]. Cognitive dysfunction, in particular memory problems, is frequent amongst survivors of out-of-hospital cardiac arrest [ 51 ], e.g., cognitive impairment four years after cardiac arrest was present in more than one-quarter of patients [ 52 ].…”